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Larry Sagers
The only good weed is a dead weed. Just make sure to pull them from your lawn after you've exterminated them.

While the weather might not be cooperating for those who want to get their tomatoes, melons and warm-season flowers growing well, there is one group of plants that has not been slowed down at all.

Weeds are like an avalanche covering the garden. The winter annuals that started growing last fall love the cool moist weather and are growing unabated. Many, such as the mustards, the downy brome and the cereal rye, are reaching maturity and shedding their pollen.

This is contributing to what might be a record year for pollen. That is not good news for allergy sufferers. To make matters worse, the summer annuals are already growing well and will further aggravate the problem.

For gardeners, the problem takes on a different dimension. Weeds are often referred to as the silent pests. While insects usually affect a specific kind of plant and diseases are even more specific, weeds are no respecter of any plants and interfere equally with all their growth.

To wage a successful war, you must know the enemy. You have to know what plant you are dealing with in order to control it. Is it a monocot (grass) or a dicot (broadleaf plant)? Is it an annual, biennial or perennial plant? Does it grow during the winter, or does it require summer heat to grow well?

Dr. Ralph Whiteside, Extension Weed Specialist for Utah State University has made that job a little easier. He has co-authored a new publication titled Common Weeds of the Yard and Garden.

He explains, "The state of Utah has listed 27 plants on their noxious weed list. An extension publication titled "Noxious Weed Field Guide for Utah" has been used extensively to teach the public about the identification and biology of the legally listed noxious weeds."

Over several years, he spent time assessing what was needed to help those in the business of weed control do a better job.

He explains, "Many horticulturists said that they had problems with commonly occurring weeds that are not on the noxious weed list and thus would like a weed identification guide that included noxious weeds but focused on weeds more commonly encountered in the yard and garden."

The book will help you because it provides information about the weeds that are most likely to occur in your garden and landscape. It lists control tactics but not control products. These include preventative, cultural or mechanical methods. These are the preferred control methods, as opposed to chemical controls, if possible.

Herbicide or weed-killer recommendations change frequently. They are best obtained from local nurseries or other experts.

Herbicides fall into several different categories. Selective broadleaf killers have been around for decades and usually have 2,4D and similar products in them. They kill plants with wide leaves (dicot), but not the grasses.

One limiting factor is that most of these products should not be sprayed when temperatures are above 85 degrees. If you are going to use them, take advantage of any cool days left.

To take grasses out of flower beds, there are other selective products. Poast and fusilade will kill grassy weeds but do not kill desirable groundcovers and shrubs. You can purchase Poast as Fertilome Over - The - Top II Grass Killer.

Ortho Grass-B-Gon contains fusilade and control grasses in ornamentals, ground covers, evergreens and other landscape plants. Do not use either of the products on lawns or ornamental grasses. For best results, apply them when the grasses are young and actively growing.

One new product that I want to make readers aware of is Ortho? Nutsedge Killer for Lawns. It contains 0.05% Sulfentrazone.

While nutsedge is not a serious problem in most Utah gardens, one of the weeds listed on the label is Star of Bethlehem. This escaped ornamental is one I am often asked how to control and one that has never had a good herbicide option.

There are many other kinds and herbicide formulations. When using any pesticide, always read and follow all label directions. Herbicide misuse is one of the most common of all plant problems.

Don't let the weeds win. Use any and all appropriate and effective means to keep them from destroying your gardens and landscapes this year.

Garden tips

"Common Weeds of the Yard and Garden" is available in printed form from local USU extension offices. To access the online version, go to extension.usu.edu, then go to the publications section.

Wasatch Community Gardens class, Building Structures for Your Garden, Saturday from 10 a.m.-noon, Fairpark Garden at 1037 W. 300 North in Salt Lake City. Learn to build trellises for climbing tomatoes, melons, squash, peas and beans. It will cover raised beds, season extenders and other devices. Register online at wasatchgardens.org.

Rocky Mountain Hosta Company Party and Hosta Sale. Friday 5 p.m.-9 p.m., Saturday 9 a.m.-1 p.m., June 3, 5 p.m. to 9 p.m. and June 4 9 a.m.-1 p.m., 1695 E. 2800 North, Layton, Phone: 801-726-3440.

Larry A. Sagers is a horticulture specialist for the Utah State University Extension Service at Thanksgiving Point.